The present invention is directed to manufacturing production line systems and methods. In particular, the present invention is directed to a system and method for integrating a production process control system (PCS) with production line machine controllers to record and track data regarding production line processes.
Automotive manufacturers today dedicate a substantial amount of resources to quality process improvements. Prior quality efforts have resulted in the development and implementation of production line systems and methods that are directed to improving various aspects of the production process. For example, U.S. Pat. No. 6,876,898, which is incorporated herein by reference, is directed to a method for identifying workstations that performed work on a part in a production line that assists production associates in determining which workstations on the line may be responsible for producing defective parts. As each part progresses through the workstations, it is marked with indicators that identify each workstation that performed work on the part. Another example as described in U.S. Pat. No. 7,086,518, incorporated herein by reference, is a system and method for bypassing workstations on a production line that may be producing defective parts. Finally, U.S. Pat. No. 7,260,441, which is incorporated herein by reference, is directed to a system and method for inspecting a part during a production run in which parts are supplied to workstations by an autoloader.
Although prior art systems and methods provide information about activities occurring at specific workstations and autoloaders for production line machinery, they do not provide information about the overall production process and do not track or provide information about the parts that have been processed through the workstations. In current systems, it is possible for parts that have not completed all required steps in a machining process to continue advancing on a production line. A process may be missed due to a malfunction that occurs in a workstation while the workstation is operating on a part. It may appear to an associate monitoring the process that the part completed the process when in fact it did not. The part may proceed through production without having completed an important process. In other instances, one or more processes may be missed because an entire area in the production line is shut down for maintenance. Efforts to avoid the non-operational equipment may result in parts proceeding through production without having completed certain processes. In either case, parts that have not been processed completely may proceed through production and cause quality problems in the resulting product.
In many cases, the fact that a part missed a production process is not obvious to a human inspector or even to a computerized inspection system. When defects attributable to missed production processes are detected, parts may be “tagged” such that a hold tag is attached to a part indicating it should not be used in production. Parts may further be physically separated or quarantined from the production process. Reliance on such physical means to detect missed process defects and to further quarantine parts, however, are not always effective in removing defective parts from production and ensuring the defective parts are not reintroduced to the production process. An associate on the production line may not realize that a part is defective or that it has been quarantined (e.g., because the tag is incorrect or falls off or because the part is not in a quarantined area) and may reintroduce the part to the production process. The resultant problems may not be detected until later in the production process or even after the production process is completed when determining the source of the problem is more difficult.
There is a need for a system and method that uses part traceability information and production process information to reduce part defects attributable to missed processes. There is a need for a system and method that integrates a production process control system with production line machine controllers to increase the likelihood that all processes in a production line are completed for each part. There is also a need for a system and method that uses part quality and traceability information to reduce the time required to locate suspect parts in an automated production line. There is a need for a system and method that improves part quality and traceability to ensure that quarantined parts are permanently removed from the automated production line. There is need for a system and method that integrates information about activities occurring at specific workstations and autoloaders with the overall production process to improve product quality.